EP 0 394 383 B1 and corresponding U.S. Pat. No. 5,049,048 disclose a hose with a cover, a liner, and an intermediate reinforcement of wire, fiber, or textile, with a channel running longitudinally through the liner. There, such a hose is proposed as a conveying hose for hose pumps. Such a pump typically has a rotor with several squeezing members which successively squeeze the hose. The channel should be connected at one end with the pump interior and be open to the atmosphere, via a non-return valve, at another end. During operation of the hose pump, the channel, like the conveying hose itself, should be clamped shut by a squeezing member and, in this manner, air is to be removed from the pump housing. In case of damage to the inner wall of the hose, conveyed product is to be released to the atmosphere and observed there.
In practice, it has been found that the desired pumping action of this channel is insufficient. A sufficient pumping action is only achieved if the channel lies outside the textile reinforcement. However, in this case, the desired warning signal of a hose break is first obtained when not only the liner, but also the textile reinforcement, have been damaged.
Transport hoses for sensitive or dangerous media are placed in service without special safety measures, particularly without indicators for hose wearout due to abrasion. The use of the conventional pumping hose as a transport hose for abrasive, dangerous or sensitive conveyable products outside a hose pump housing is not known.